BUG REPORT - product detail page messes up

Could you give a link to that page so that we can see the problem ?

We don't have that problem on our end so it's hard to say anything without more info.

did you change something in one of the view files of the product view ?

It seems to be a bug resulting from recent changes to the show layout file.
Could you edit the file "show" of the view "product" via the menu Display->Views and change the line:
$height = $this->config->get('thumbnail_y');

to:
$height = $this->config->get('product_image_y',$this->config->get('thumbnail_y'));

That should help fix the problem.